Hello,
I am also looking into Alice Green & Andrew Cavanagh.
The info I have so far (which is probably the same as you do) is:
Married 26/08/1866 in Arklow, Wicklow
Alice's father was John Green. Andrews father was James Kavanagh
Children:
Margaret 1867 - Coolgreaney, Wexford
Catherine 1868 - " "
Alice 1871 - Dublin
James 1874 - Widnes, Lancs
Thomas 1877 - "
Annie 1879 - "
Patrick 1881 - "
John 1883 - "
Charles 1886 - "
Andrew died March 1891 (I did note on the '91 census after his death & the family have moved they are living next to a Thomas Green from Ireland, but this may be coincindence).
I will let you know if I find any more info...